NCJ Number
51788
Journal
Journal of Forensic Sciences Volume: 23 Issue: 4 Dated: (OCTOBER 1978) Pages: 672-678
Date Published
1978
Length
7 pages
Annotation
A TECHNIQUE IS PRESENTED WHICH ALLOWS FOR THE SEQUENTIAL INFRARED SPECTROPHOTOMETRY (IR) AND PYROLYSIS-GAS CHROMATOGRAPHY (PGC) ANALYSIS OF A SINGLE PAINT SAMPLE. THESE TECHNIQUES HAD BEEN ASSUMED TO BE EXCLUSIVE.
Abstract
HERETOFORE, THE LITERATURE HAS INDICATED THAT PGC AND IR ANALYSES CANNOT BE PERFORMED ON THE SAME PAINT SAMPLE BECAUSE THE SPECTROGRAPHIC-GRADE POTASSIUM BROMIDE (KBR) POWDER USED TO FORM PELLETS FOR IR ANALYSIS IS CONSIDERED DESTRUCTIVE TO THE SAMPLE. A TECHNIQUE WHICH HAS BEEN USED SUCCESSFULLY TO ANALYZE A SINGLE 0.5 MILLIMETER KBR PELLET CONTAINING A PAINT SAMPLE, FIRST BY IR, THEN BY PGC ANALYSIS, IS DESCRIBED. THE BASIS OF THE TECHNIQUE IS THE USE OF 'SPECTRANALYZED' METHYLENE CHLORIDE AS A SOLVENT AFTER GRINDING THE PAINT SAMPLE AND THE KBR POWDER TOGETHER. THE RESULTING PELLET IS EASILY ANALYZED BY BOTH IR AND PGC. IF THE SAMPLE WERE SUFFICIENTLY LARGE, THE PELLET POSSIBLY COULD BE SUBJECTED TO ANALYSIS BY EMISSION SPECTROSCOPIC TECHNIQUES AS WELL. THE TECHNIQUE IS ILLUSTRATED USING A SAMPLE OF STANDARD AUTO BODY PAINT. THE RESULTING CHROMATOGRAPHS ARE REPRODUCED. REFERENCES ARE PROVIDED. (GLR)